The present invention relates generally to systems for communicating sensor information to a vehicle control computer, and more specifically to such systems for communicating sensor information over a vehicle data bus.
Automotive control systems typically include a number of engine and/or vehicle operating condition sensors and sensing systems which provide corresponding sensor signals to a control computer. The control computer, which may be an engine/vehicle control computer or other control computer associated with an automotive control module, is in turn responsive to the sensor signals to control an associated automotive component.
In some automotive systems, the number of required sensors may be small and/or a sufficient number of control computer inputs may be readily available so that the sensors may be wired directly to corresponding inputs of the control computer. An example of one such system is illustrated in U.S. Pat. No. 5,392,024 to Kiuchi et al. In recent years, however, the number of automotive sensors or sensing systems have increased and/or the number of available control computer inputs have decreased, and a need to accommodate such a disparity has thus arisen.
Designers of automotive control systems have responded to the proliferation in automotive sensors and sensing systems by designing signal multiplexing systems operable to combine sensor signals, thereby reducing the total number of signal paths required for connection to the associated control computer. Some such multiplexing systems have realized a significant reduction in the number of required signal paths by including communication circuitry for broadcasting the multiplexed signals over a vehicle data bus, or so-called datalink, that is connected to the control computer. An example of a known multiplexing system of the type just described is disclosed in U.S. Pat. No. 5,512,890 to Everson, Jr. et al.
While sensor signal multiplexing systems of the type described by the Everson, Jr. et al. reference address many of the concerns relating to sensor proliferation as discussed hereinabove, these systems have certain drawbacks associated therewith. For example, such systems require the sensors to be individually connected to the multiplexing system, thereby requiring an unnecessarily complex wiring harness that invites potential electromagnetic interference as well as reliability problems. U.S. Pat. No. 5,808,689 to Rado et al. discloses a multiplexing system that locates the multiplexing units proximate to the sensor units, but still requires an unnecessarily complicated albeit shorter wiring harness.
What is therefore needed is a sensor multiplexing system that allows for the broadcasting of multiple sensor signals over a vehicle data bus while also minimizing wiring harness connections between the various electrical components.
The foregoing shortcomings of the prior art are addressed by the present invention. In accordance with one aspect of the present invention, multi-sensor module for communicating sensor information over a vehicle data bus comprises a plurality of sensors producing a plurality of sensor signals indicative of a corresponding plurality of vehicle operating conditions, a first signal processing circuit receiving the plurality of sensor signals and producing a time-division muliplexed signal representative of the plurality of sensor signals according to a first vehicle data bus communications protocol, and a housing having the plurality of sensors and the first signal processing circuit mounted therein.
In accordance with another aspect of the present invention, a multi-sensor module is connected to a vehicle control computer via a vehicle data bus, wherein the multi-sensor module comprises a plurality of sensors producing a plurality of sensor signals indicative of a corresponding plurality of vehicle operating conditions, a signal processing circuit receiving the plurality of sensor signals and producing at an output thereof a time-division muliplexed signal representative of the plurality of sensor signals according to a vehicle data bus communications protocol, a housing having the plurality of sensors and the signal processing circuit mounted therein, and a connector mounted to the housing, wherein the connector defines one end connected to the output of the signal processing circuit and an opposite end connected to the vehicle data bus.
One object of the present invention is to provide a sensor module configured for mounting multiple sensors therein and equipped with communications circuitry capable of broadcasting on a vehicle data bus information corresponding to sensor signals produced by each of the sensors mounted within the module.
Another object of the present invention is to provide such a module capable of broadcasting sensor information on the vehicle data bus in accordance with any known vehicle data bus communications protocol.
Yet another object of the present invention is to provide such a module that is sufficiently flexible in design to permit a wide variety of sensors to be mounted within the module, and to further permit broadcasting of the sensor information according to a number of different vehicle data bus communication protocols.
These and her objects of the present invention will become more apparent from the following description of the preferred embodiment.